With at least three spots still open on its Olympic roster, USA Basketball extended formal invitations to Shaquille O'Neal and Kevin Garnett, ESPN.com has learned.

USAB officials, according to sources, are increasingly optimistic that both All-Stars will agree to sign on, which would significantly strengthen an American squad somewhat short on size. Garnett's participation is seen as the more likely of the two.

Asked if he would play, O'Neal told The Associated Press on Wednesday, "I don't know yet. They are asking me. I
haven't decided yet. I have to decide.''

Garnett remains undecided too, claiming his focus is currently elsewhere.

"I haven't given it any thought, to tell you the truth,"
Garnett said Thursday night after his Timberwolves lost
to the Spurs 106-86.

Asked when he will decide, Garnett said, "I have no timeline.
I'm focused on the season and the Minnesota Timberwolves."

Should they accept, O'Neal and Garnett would join a frontcourt rotation that, at present, is limited to Tim Duncan, Jermaine O'Neal and Karl Malone. But Shaq and KG have been noncommittal about their plans publicly, both saying they are torn between representing their country again and letting new faces carry the flag.

Bryant didn't play for the qualifying team after being accused of sexual assualt in Colorado and was replaced by Vince Carter. Malone was a late withdrawal after the death of his mother and was replaced by Kenyon Martin.

This time around, if O'Neal accepts and Bryant and Malone are able to play, the Los Angeles Lakers would have three players on the team.

"For Karl, he's a bionic man. He can stay in shape," Lakers
coach Phil Jackson said. "For Shaq, it might not be the best idea.
It's an honor for a ballclub. I can't remember three guys from one
team playing."

Malone, however, has said
he might withdraw from the team if his knee isn't 100 percent.

Also, O'Neal said last month that he was undecided about making a
seven-week commitment to the U.S. team.

"I think it is very, very burdensome. It depends how far we
(the Lakers) go in the season," O'Neal said. "I have to consult
with my family and consult with my friends. I'm not sure what I'm
going to do."

O'Neal was a member of the U.S. team that won the gold medal in
the 1996 Atlanta Olympics. He declined an offer to play for the
American team in Sydney.

Garnett, who played for the U.S. team in 2000, also has said he
is undecided about playing in Athens.

Last summer's team also included Elton Brand, Nick Collison and Richard Jefferson, but those three -- along with Carter and Martin -- were given no guarantees they'd be picked for the actual Olympic team.

Additional roster spots could open even if Shaquille O'Neal and/or Garnett accept the invitations. Bryant's forthcoming trial could prevent him from playing, and it remains to be seen whether Duncan and Malone -- both slowed by knee injuries this season -- will be willing or able to play through the most lengthy preparations undertaken by a U.S. national team stocked with NBA players.

Coach Larry Brown will convene the group in Florida on July 26 and work with it for more than a month, with exhibition stops scheduled in Germany, Serbia and Montenegro, and Turkey before proceeding to Athens. The Olympics are Aug. 15-28.

Carter and Brand are the favorites to claim roster spots depending on what remains open after O'Neal and Garnett make their decisions. Brad Miller, Ben Wallace and Martin also have been mentioned as frontcourt possibilities if Team USA ends up needing size.

Chris Webber and Zach Randolph have not been considered by the selection committee to date, with USAB officials continuing to place a huge emphasis on good citizenship in addition to on-court qualifications. Webber and Randolph have faced high-profile legal issues in recent months; Bryant, by contrast, has not been affected by the charges against him because they came after he was selected.

Brown and potential teammates have been pushing for the participation of O'Neal and Garnett in hopes of sending the strongest possible squad to Greece. Since NBA players started participating in 1992, Team USA is unbeaten in winning three gold medals; however, the Americans were nearly beaten twice by Lithuania at the Sydney Olympics in 2000. USA Basketball, meanwhile, is still reeling from its three losses -- resulting in a sixth-place finish -- at the 2002 World Championships in Indianapolis.

Marc Stein is the senior NBA writer for ESPN.com. To e-mail him, click here. Also, click here to send a question for possible use on ESPNEWS.